CALF SCOURS-THE BIGGEST KILLER OF CALVES:PREVENTION & MANAGEMENT

Neonatal calf scour is one of the most common illnesses seen in young calves.

The economic losses of calf scour incurred on-farm can be substantial due to calf mortality, treatment costs, weight loss and subsequent poor growth rates. Calf scours is the most common symptom of illness in young calves and can be caused by several different viruses, bacteria and organisms. Most often it is a problem in the first month of life. Viruses like the rotavirus (most common) and bacteria like salmonella and E.coli, as well as coccidian and other internal parasites can cause scours. When attacked by these infectious agents, the calf’s gut is still so immature; making it the weakest point of the calf’s system, the lining of the bowel is damaged and results in the loss of large amounts of body fluid into the gut. The calf is quickly dehydrated, electrolytes are unbalanced and energy reserves become depleted. A calf is approximately 70% water at birth, so the loss of body fluids through diarrhea produces the rapid dehydration. The younger the calf, the greater the chance of death.

It is a most common problem during the first weeks of life and is frequently fatal. It is the result of changed gut function; that is, the germ makes the gut stop digesting, which increases the amount of manure and fluids the calf passes. Calves on a milk diet normally pass only a small amount of droppings. If the gut is affected, the amount passed can increase markedly. For example, the amount of water passed in a scouring calf can be 20 times normal. This extra water is mixed with salts and other food, so the calf is losing more than it can eat. The loss of water and salts leads to dehydration. This causes shock and death. In other words, the germ that started the scour is usually not the direct cause of death. It is the shock caused by the loss of body water and salts that is the actual cause of death.

Causes:
There are four major causes of scours:

·    E. coli (white scours)

·    Salmonella

·    Rotavirus

·    Cryptosporidia

All these can occur separately or together.

Signs and Symptoms:
There is profuse watery diarrhea, progressive dehydration and acidosis. Calf is dull and lethargic and in many cases dies in a short time.

Treatment:

The immediate treatment and most important is to administer fluids, electrolytes and energy. Fluid is essential, but the fluid cannot be absorbed from the gut unless it contains electrolytes (salts) in proper proportions. Scouring calves should receive at least 10% of body weight of fluids and electrolytes if scouring is mild, and more if it is severe. Use a high quality electrolyte mixture administered with a stomach tube, twice daily.

Don’t mix the fluid and electrolytes with milk, as it will cause the milk to curdle and be of no benefit. Consult with a veterinarian on whether to use antibiotics, as some antibiotics can increase the severity of scours, and can cause muscle damage.

 The most important thing to do is to replace the lost body water and salts. This is done by using electrolytes in their correct concentration. The earlier this is done, the better the response. Antibiotics can be used if necessary. Make sure affected calves are warm and dry. Exposure to the weather when sick will make things worse.

Unfortunately, calf scour – even under strict management practices – still occurs. When it does, a net loss of fluids occurs in the animal. The calf is losing more fluids than it is receiving from the diet.

This quickly leads to a dull, depressed and dehydrated animal.

A number of steps should be taken once the scouring calf is noticed:

·         Step 1: Separate the calf from the group to help stop the spread of disease;

·         Step 2: Administer oral rehydration therapy (ORT);

·         Step 3: Continue to feed milk.

ORT is the single most important therapeutic measure to be carried out to help correct the dehydration, acidosis and electrolyte imbalance that occurs in scouring calves.

Prevention of scours

There are several management strategies to help prevent scours from infecting your calf crop.

• Calve heifers in a separate area from older cows. Their calves’ immunity levels are typically lower than calves from older cows.

• Avoid wet calving barns and areas if possible. Try to calve on pasture if the weather permits. The ideal calving environment would be a fairly steep hillside pasture with a windbreak, accompanied by warm, dry weather. One of the primary causes of scours is a wet, muddy and cold calving environment.

• Provide portable calf shelters on pasture to keep calves dry and protected from chilling winds. It is also essential that these sheds be moved or cleaned out periodically.
If calving in smaller spaces, turn the cow/calf pairs out to a clean pasture area as soon as possible.

• Isolate any scouring calves and treat immediately. Clean and disinfect the environment. Early isolation is critical to help aid in preventing the spread of scours to other calves.

• Have cows and heifers in good body condition, and on an appropriate nutrition program to help ensure calves are born healthy and strong.

• Vaccinate herd six and three weeks prior to the beginning of the calving season. Follow label instructions. Don’t rely exclusively on vaccines, as they can’t be 100% effective if the calves are born in a muddy area that is already infected with diseases.

• Make sure that newborn calves receive adequate amounts of colostrum.

·    The most important method of prevention is to provide adequate colostrum (beestings) in the first few hours after birth.

·    Provide adequate housing or shelter from the weather to reduce stress. Stress is important in allowing scours to develop.

·    Maintain a suitable management and feeding system. Overfeeding and sudden changes of diet can cause further stress.